Slagging furnace



June 15, 1937.

W. E. CALDWELL ET AL SLAGGING FURNACE Filed Sept. 26, 1934 Q l V NT R5 mm; M ATTORNEYS Patented June 15,. 1937 PATENT OFFICE SLAGGING FURNACE William E. Caldwell, New Rochelle, and Edward H. Man, Mamaroneck, N. Y.

Application September 26. 1934, Serial No. 745,496

2 Claims.

Another object of the invention is the provision" of a bottom for such furnaces in which destruction and washing out or erosion of portions of 10 the bottom by slag being discharged is avoided.

How the foregoing together with such other objects and advantages as may hereinafter appear or are incident to our invention are realized is illustrated in preferred form in the accompany- 16 ing drawing, wherein- Fig. 1 is a vertical section through a portion of the bottom of a furnace constructed in accordance with our invention;

Fig. 2 is a plan view of thecooling means 10- 20 cated marginally of the slag discharge opening illustrated in Fig. 1; i

Fig. 3 is a plan view illustrating a modified form of cooling means.

Referring to Fig. l, the bottom A of the furnace is constructed to retain a stagnant bed of molten slag indicated at B and comprises a top layer 6 of refractory aggregate, a layer 1 of plastic refractory, a metallic backing 8 and filling material 9 such as concrete located between the layer 1 and the backing 8. Air cooling tubes It! may be imbedded in the filling material 9.

An overflow opening I l is provided in the bottom A for the discharge of liquid slag whereby a predetermined level of molten slag is maintained 5 in the bottom.

The overflow opening is preferably located centrally of the bottom in the upraised portion I! the height of which determines the depth of the bed of molten slag. 40 In order to prevent erosion of the material at the opening by the discharging molten slag. provision is made for marginally cooling the opening and as illustrated in Figs. 1 and 2, we employ cooling means in the .form of a coil of 5 tubing l3 through which a cooling medium such as water is circulated by means of inlet and outlet tubes l4 and I5 respectively. This coil or .oth'er cooling tubes may be embedded in suitable material l6, such as magnesite provided at the 50 opening.

It is to be observed that the overflow opening is entirely surrounded by a pool of slag and is located in a region where the heat in the combustion chamber is most effective in maintaining discharge.

By providing a fluid cooled overflow openin for the discharge of the liquid slag, difficulties heretofore encountered at the overflow are overcome. For example, it has been found that installations having overflow outlets not equipped with our invention have been very expensive to maintain because of the fact that the lip around the'opening was extremely diiflcult to maintain, it being pointed out that the discharging slag washed the lip down and as the level of the lip 10 receded, the refractory floor of the furnace was also washed down to a comparable level with the result that the whole floor gradually wasted away. Through the-practice of our invention, not only is the lip around the opening maintained, but wasting away of the floor is also prevented.

A chamber 0 is locatedbeneath the overflow opening ll into which the overflowing slag is discharged. A water sluice l1 seals the chamber C and the falling slag is quenched by the sluice water. Gas oiftakes l8 leading to a gas passage of a boiler associated with the furnace may be provided for the chamber C and if desired the slag may be cooled by means of water introduced by spray devices l9 and 20 provided in the chamber.

In Fig. 3 a modified form of cooling means is disclosed comprising a tubular ring 2| through which cooling water is circulated as by means of theinlet and outlet water tubes 22 and 23. Other cooling tubes such as the tubes 24 may be .associated with the ring 2|. f

The furnace may be fired with slag producing A \fuel such as pulverized coal which may be intro- 3.3

duced into the combustion chamber of the furnace by suitable burners. We also contemplate applying my inventionto furnaces in which a stagnant bed or material is maintained as by a Y 'flame sweeping over. the molten surface from an 40' adjoining furnace.

We claim:

1. In combination, a furnace, a bottom for the furnace having a relatively small opening extending therethrough, said bottom except for said opening being constructed to prevent liquid slag from passing therethrough so that there is a concentration of slag flowing from the entire furnace bottom to and through said opening, a dam surrounding said opening having a slag drip lip, and cooling means adapted to the contour of said dam and lip cooperating therewith to maintain a pool of slag adjacent the opening and to protect the dam and lip against destruction by the concentrated mass of flowing slag.

v 2. In combination, a furnace, a bottom for the furnace having a relatively small opening extending therethrough, said bottom except for said opening being constructed to prevent liquid slag from passing therethrough so that there is a concentration of slag flowing from the entire furnace bottom to and through said opening, a slag drip li arranged peripherally of said opening, and cooling means for continuously cooling said drip lip to protect it against destruction by the concentrated mass of flowing slag.

W. E. CALDWELL. EDWARD H. MAN. 

